Cephalosporin compositions

ABSTRACT

An antibiotic composition having as essential components (A) a broad spectrum cephalosporin antibiotic subject to degradation by a Beta -lactamase and (B) a cephalosporin antibiotic resistance to degradation by the Beta -lactamase whereby the broad spectrum antibiotic is protected against such degradation.

United States Patent Cynthia Hilda O'Callaghan Gerrards Cross, England 647,303

June 20, 1967 Nov. 30, 1971 Glaxo Laboratories Limited Greenlord, England [72] Inventor 21 Appl. No. [22] Filed [45] Patented [73] Assignee [32] Priority June 24, I966 [33] Great Britain 28,522/66 [54] CEPIIALOSPORIN COMPOSITIONS 28 Claims, No Drawings [52] U.S. Cl 424/246 [51] Int. Cl ....A6lk 21/00 [50] Field of Search 424/246; 260/243 C [56] References Cited UNITED STATES PATENTS 3,216,999 1 111965 Flynn 260/243 C FOREIGN PATENTS 1,030,630 12/1963 Great Britain 260/243 1,028,563 12/1963 Great Britain 260/243 OTHER REFERENCES 0 Callaghan, Cynthia et al., Antimicrobial Agents & Chemotherapy 1966) p. 337- 343 Sabath, L. D. et al. 1, Nature, Vol. 204, pp. 1066- 1069 (1964) Sabath, L. D. et al. 11, Biochemical Journal, Vol. 96, pp. 739- 752 (1965) Hamilton-Miller, .l. M. T. et al., Nature, Vol. 208, pp. 235- 237(1965) Wick, Warren et al., Applied Microbiology, Vol. l2, pp. 248- 253 (1965) Primary Examiner-Sam Rosen Attorney-Bacon & Thomas ABSTRACT: An antibiotic composition having as essential components (A) a broad spectrum cephalosporin antibiotic subject to degradation by a B-lactamase and (B) a cephalosporin antibiotic resistance to degradation by the B- lactamase whereby the broad spectrum antibiotic is protected against such degradation.

CEPHALOSPORIN COMPOSITIONS This invention is concerned with improvements in or relating to antibiotics of the cephalosporin series, i.e., derivatives of 7-aminocephalosporanic acid.

The discovery of cephalosporin C and the subsequent isolation of its nucleus, 7-aminocephalosporanic acid, has led to the development of a number of derivatives of the latter having broad spectrum activity as antibacterial antibiotics. The most important of such derivatives to date is the substance known by the common name cephaloridine, although other cephalosporin compounds of lesser activity but still possessing broad spectrum activity are of interest.

Unfortunately, these broad spectrum cephalosporin antibiotics are not active against certain important gram negative organisms principally strains of Aerobacter and Proteus organisms. Investigations have shown that certain Proteus organisms, e.g. Pr. vulgaris, Pr. rengeri, Pr. morgani and certain organisms of the coliform type e.g. of the genera Aerobacter, Enterobacter, Klebsiella, Hafnia and Citrobacter produce enzymes which open the four-membered lactam ring of the antibiotics and inactivate them. It will be appreciated that some bacteriologists describe Entembacter organisms as being Aerobacter organisms. We have used the term Enterabacter to describe nonmotile organisms and "Aerbacter to describe motile organisms (see Manual for Identification of Medical Bacteria" Cowan and Steel, 1965, Cambridge University Press, England). Confirmation of this has been obtained by proton magnetic resonance and/or ultraviolet spectra measurements of the inactivated compounds. it would, therefore, appear that the antibiotics are unable to kill the organisms owing to the more rapid action of the B-lactamases on the antibiotics. This not only lessens the effective range of activity of the antibiotics but also reduces the efficiency of the antibiotics, when there is simultaneous infection by a sensitive organism and a B-lactamase producer.

As a result of our researches we have found that various cephalosporin antibiotics are substantially resistant to degradation by the above-mentioned B-lactamases although in general are of minor importance as antibiotics (having a narrow spectrum and/or low degree of activity). We have further found that selected members of such B-lactamase-resistant antibiotics when combined with the above-mentioned broad spectrum antibiotics protect the latter against B-lactamase degradation thereby rendering the broad spectrum antibiotic effective against such fl-lactamase producing organisms. This enhances the spectrum and/or degree of activity of the broad spectrum antibiotics without detracting from two of their principal and highly important advantages, viz their relative inertness to staphylococcal pencillinase and their utility in treating penicillin hypersensitive patients. Surprisingly, the cephalosporin antibiotics which are considerably less susceptible to degradation by the B-lactamases are themselves largely inactive against the organisms responsible for the lactamases.

According to the present invention, therefore, there is provided an antibiotic composition comprising (A) a broad spectrum cephalosporin antibiotic subject to degradation by a B lactamase produced by Proteus morgani and (B) a cephalosporin antibiotic resistant to degradation by said B-lactamase whereby said broad spectrum antibiotic is protected against such degradation and its spectrum and/or degree of activity thereby improved.

As to whether a B-lactamase-resistant cephalosporin antibiotic is suitable for use in the composition according to the invention may be simply determined by in vitro experiments as hereinafter described.

The term broad spectrum antibiotic" is used herein in its generally accepted sense (see The Pharmacological Basis of Therapeutics, Third Edition by Goodman and Gilman, The MacMillan Co. New York, USA. page 1,173) to denote antibiotics which are effective against both gram positive and gram negative organisms, principally S. aureus (gram positive) and E. coli and Pr. mirabilis (gram negative).

Particularly effective fl-lactamase-resistant antibiotics (B) are compounds of the formula:

m CQIH (I) or a salt thereof with nontoxic cations, e.g. sodium or potassium, wherein R is (i) a carbocyclic aromatic group (preferably a phenyl group) containing at least one substituent in an ortho position (ii) a 3-aryl-5-methyl-isoxazol-4-yl group or (iii) a l,l-disubstituted aralkyl group, and R is the acetate or the azide group.

The expression ortho position" indicates a position in the group immediately adjacent to the point of attachment of the aromatic group to the carbonamido group of formula I.

Other compounds of formula I which may be used include those wherein R is a 3-aryl-5-methyl-isoxa.zol-4-ylmethyl group, a l-bromobutyl group, a l-chloro-l-phenyl-methyl group, a Z-thienyl group, a Z-pyridyl group or a bis-(thien-2- yl)methyl group.

The invention includes within its scope as new compounds, compounds of the formula:

s R30 ONEj and salts thereof with nontoxic cations, e.g. sodium or potassium, wherein R is 2-chlorophenyl, phenyl substituted with lower alkylthio in at least one ortho position, phenyl substituted with lower aralkylthio in at least one ortho position, 2,4,6-triloweralkylphenyl, 2,4,6-triloweralkoxyphenyl, 3-aryl- 5-methyl-isoxazol-4-yl,

s 3 .0 01mg o (III) where R is 2-thienylmethyl or D-a-amino-a-phenylmethyl and R is acetate or, in betaine form with the adjacent carboxyl, Py" (where Py is N-pyridyl or substituted N-pyridyl e.g. nicotinamido or isonicotinamido). Examples of such antibiotics are described in British Pat. Nos. 1,028,563 and 1,030,630. It is particularly preferred to use the compound which forms the subject of British Pat. No. 1,028,563 which is known by the common name of cephaloridine and by the systematic name of N-7-(2-thienylacetamidoceph-3-em-3-ylmethyl)-pyridinium-4-carboxylate, although it is to be specifically understood that the invention is not limited to the use of this preferred compound. Other compounds of this type which may be used include compounds of the formula where R is selected from carbamoyl, lower alkyl, hydroxy, hydroxymethyl, carboxy, carboalkoxy, lower alkylcarbamoyl, cyano, etc.

Other cephalosporin antibiotics (A) of fonnula III which may be used include cephalothin viz 3-acetoxymethyl-7-(2'- thienylacetamido)-ceph-3-em-4-carboxylic acid as the sodium or potassium salt and described and claimed in British Pat. No. 982,252; and 3-acetoxymethyl-7-D-a-amino-a-phenylacetamidoceph-3-em-4-carboxylic acid ("cephaloglycin") described and claimed in British Pat. No. 985,747.

Where the group R in the compound of formula I is an ortho-substituted phenyl group this may be a mono-ortho-substituted phenyl group wherein the ortho substituent is, for example, lower alkyl, lower aralkyl, lower alkylthio, lower aralkylthio, lower alkoxy' or halogen e.g., chloro, bromo or iodo. However, the group R preferably has the structure:

where Q= and Q, which may be the same or different are each lower alkyl, lower alkoxy or halogeno (e.g., chloro) and Q is a hydrogen atom or has any of the meanings attributed to Q' and Q. Some of these compounds form the subject of British Pat. Nos. 951,48 l and 953,696. The group R may also be a-naphthyl and this compound (R acetate) is described in U.S. Pat. No. 3,216,999.

Where the group R in formula II is a 3-aryl-5-methylisoxazol-4-yl or a 3-aryl-5-methyl-isoxazol-4-ylmethyl group, the aryl group may, for example, be phenyl or phenyl substituted with halogen, e.g. chlorine or bromine.

The l, l -disubstituted aralkyl group may have the formula where Ar is an aromatic group and Z is a bivalent hydrocarbon group e.g. the group(CH n being 2, 3 or 4, or the group where m is or integer and R is a lower alkyl etc. group.

The compounds of formulas l and ll may be prepared by condensation of a compound of the formula:

or a salt thereof, wherein R is a hydrogen atom or the group RCO or R CO, and R has the above-defined meaning with (l) where R is a hydrogen atom, an acylating agent of the acid R'COOl-l or R COOH, as appropriate, followed by condensation of the resulting compound, if desired, with an alkali metal azide, if a compound wherein R azide is desired and a starting compound wherein R acetate is used;

(2) where R is RCO or R co and R acetate, an alkali metal azide to obtain a compound wherein R azide.

Acylating agents of the acid RCOOH and R"COOH may be any convenient acylating agent which yields the desired side chain e.g. the corresponding acid chloride or bromide, a mixed anhydride derived from the acid and an alkyl haloformate or the free acid in the presence of a carbodiimide. The acylation is conveniently carried out in an aqueous medium or an appropriate organic solvent and preferably in the presence of an acid binding agent.

The reaction with alkali metal azides may be effected as described in British Pat. No. 1,021,943.

Combinations of (A) and (B) which are particularly preferred are (l) cephaloridine and 3-acetoxymethyl-7-(2, 6-dichlorobenzamido)-ceph-3-em-4-carboxylic acid (or the sodium or potassium salt thereof); (2) cephaloridine and 3 acetoxymethyl-7-(2, 4, 6-trimethylbenzamido)-ceph-3-em- 4-carboxylic acid (or the sodium or potassium salt thereof) (3) cephaloridine and 3-acetoxymethyl-7-(2', 6'-dimethoxybenzamido)-ceph-3-em-4-carboxylic acid (or the sodium or potassium salt thereof) and cephaloridine and 7-[3'-(2"- chlorophenyl)-5'-methylisoxazole-4-carbon-amido-]ceph-3- em-4-carboxylic acid (or the sodium or potassium salt thereof),

Compounds (A) and (B) may be used in a ratio by weight of from about 95:5 to about 5:95 correspondingly e.g. from :20 to 20:80. Preferably compounds (A) and (B) are used in a ratio by weight from about 2:1 to about 1:2 respectively, and conveniently about 1:1. It should be noted that even small amounts of compound (B) show a degree of protection for compound (A).

Compounds (A) and (B) may be formulated as a mixture for simultaneous administration. Thus, if compound (A) is normally administered parentally, as is the case with cephaloridine, then compounds (A) and (B) may be prepared as a dry mixture to which sterile pyrogen-free water may be added before use to form an aqueous solution of the desired concentration.

It is, however, not necessary to administer compounds (A) and (B) simultaneously and if desired they may be separately administered e.g. (A) followed by (B) or (B) followed by (A).

in general unit dosages of the compositions in human medicine on adults will range from 200 mg. to 1.5 g. or higher of compound (A) with a corresponding amount of compound (B) per dose, administered for example 2-5, conveniently 3 times a day.

In general the dosages and daily dose schedules will be determined in accordance with the infection being treated and the condition of the patient as is usual in antibiotic therapy. Larger doses than those referred to above may sometimes be required and may for example be given by intravenous drip.

Compositions for injection may be in powder form for reconstitution with a suitable vehicle, for example, sterile pyrogen-free water or may take such forms as solutions, suspensions or emulsions with aqueous or nonaqueous vehicles, and may contain carriers and excipients known in the art to assist formulation, such as suspending, stabilizing, dispersing, solubilizing and emulsifying agents. Examples of suitable vehicles include physiological saline, parenterally acceptable oils and oily esters such as arachis oil, isopropyl myristate, and water-miscible solvents such as propylene glycol.

The suspending agents may be, for example, sorbitol or carboxymethylcellulose for aqueous preparations, or aluminum stearate gel for oily vehicles. Suitable stabilizing agents include sequestering agents, such as sodium edetate; pH buffers,

may be presented as individual capsules, in liquid or semisolid form, or may be used as drops, etc. Topical applications may be formulated in hydrophobic or hydrophilic bases as ointments, creams, lotions, paints, powders etc.

such as disodium hydrogen phosphate and sodium dihydrogen 5 For veterinary medicine, the compositions may, for examphosphate; antioxidants and preservatives such as sodium ple, be formulated as intramammary preparations (veterinary sulfite and sodium formaldehyde-sulfoxylate. Lecithin and cerates) in i h o gg r quick-release bases. polyethylene glycol-600 monoleate are examples of suitable The compositions of the invention for human or veterinary dispersing agents. Parenterally acceptable emulsifying agents use may contain additional active ingredients e.g. other anmay be chosen from a wide range of surface-active agents to 10 tibiotics. give either water-in-oil or oil-in-water emulsions, for instance, The composition may be presented as a two container pack, pentaerythritol dioleate, propylene glycol oleate, sorbitol one container containing compound (A) and the other conmonostearate, or colloidal materials such as acacia and taining compound (B). gelatin- 1 5 We now give, by way of example only, methods of assaying The compositions. where pp p ia e, may be presen ed in susceptibility of broad spectrum cephalosporin antibiotics to a form suitable for absorption by the gastrointestinal tract. B-lactamases and methods of selecting B-lactamase resistant Tablets and capsules for oral administration may be in unit cephalosporin antibiotic protectors. dose Presentafion form and y Contain Conventional Cells were removed from 48 hr. cultures by centrifuging, cipiems such as binding agents, for example, Y P- acacia, oi and resuspended in fresh nutrient broth to one-tenth original g Sorbilol, tragacanth, p y nylpyrollidone; fi l lvolume, containing about 10 viable cells. The suspensions for example, lactose, sugar, maize-starch, calcium phosphate, lwere diluted with nutrient broth in a doubling series, and to sol'bilol g y lubricants. for ple. m gn i m each dilution an equal volume of antibiotic substrate was sieal'ate, talc. p y y g y Silica; g ts, r X- added, so that each tube contained 4 ml. suspension and 250 ample potato starch or acceptable wetting agents, such as pgJml. substrate. The tubes were incubated at 37 C. for2hr. sodium lauryl sulfate. The tablets may be coated according to and the residual antibiotic was estimated by large (12x12) methods well known in the art. Oral liquid preparations may late bio-a ay, From the tube' having the nearest amount to be in the form of aqueous or y p n i ns. ol i n m l- 125 ug/mi. of remaining substrate (i.e., 500 inactivation), the sions, syrups, elixirs, etc. or may be presented as a dry cell dilution required to destroy l25 #g/ml. in 2 hr. was calcuproduct, for reconstitution with water or other suitable vehicle lated. To facilitate comparison between the activities of before use. Such liquid preparations may contain convenseveral organisms against one substrate, or of one organism tional additives such as suspending agents, for example, soragainst several substrates, this cell dilution was multiplied by bitol syrup, methyl cellulose, glucose/sugar syrup, gelatin, 125, and the results expressed as the theoretical amount of hydroxyethylcellulose, carboxymethylcellulose, aluminum compound that 1 ml. of the original cell suspension would stearate gel or hydrogenated edible fats; emulsifying agents, destroy in 2 hr. This method of assessing antibiotic inactivafor example, lecithin, sorbitan mono-oleate or acacia; tion was used as we wished to study living cells undergoing cell nonaqueous vehicles which may include edible oils, for examdivision at antibiotic concentrations low enough to be found in ple almond oil, fractionated coconut oil, oily esters, propylene h bodyglycol, or ethyl alcohol; preservatives, for example, methyl or In the following table we give an in vitro assessment of the propyl p-hydroxybenzoates or sorbic acid. Suppositories will protection afiorded to Cephaloridine (87/4) from B-lactamase contain conventional suppository bases, e.g. cocoa butter or attack using various cephalosporin compounds (8) as protecother B yceride. tors. The (B) compounds were tested for their sensitivity to ,B- The composition may also be prepared in suitable forms for lactamases produced by Pr.m0rgani NCTC 235 and Enabsorption through the mucous membranes of the nose and rerobacter cloacae P99, a virulent member of the Aerobacter throat or bronchial tissues and may conveniently take the subgroup A and previously known asA.aer0genes, isolated by form of powder or liquid sprays or inhalants, lozenges, throat Dr. P. C. Fleming of The Research Institute, The Hospital for paints etc. For medication of the eyes or ears, the preparations Sick Children, Toronto, Canada. Cephaloridine was tested in TABLE 1 Protection 0! 87/4 by Compound B Resistance of B to- B against R1 R2 P99 NCTC235 Pill) NCTC235 ,923 Infinit 41 Infinity. ii ii iiifi iiiiisijjj *ififfffi-.. in imty 7.. essiaen? .d. Amie.-. N331.-. Nai Do: 2,4,6-tr1methoxyphenyl Acetate.-- Infinity. Infinlt D0- o-Methylmercaptophenyl. do.... 659 .do Do. o-BenzylmercaptophenyL-. D0. 3-phenyl-5-methylisoxazol-4-y 13g: aee fiiiihni i -ifietifiiiiii-LiziIIIIII: 6 1 3-(o filchibiuriiieiifi ifiiiiii l isbraillil I AcetaE g 3-0-ch%6 3h e ii 5 ifieth1 is6iainf-iii 3-fio-dichlorophenyl)-5-methyl-isoxazoi-4-yl- D iiiii j Azide" D0. l-bromobutyl l-chlorml-phenyl-methy 88. P enyl Do: 2-thienyl D 2-pyridyl Bis(thien y :methy Do- 2-phenyl-L3-drth an-2-yl- D o. 2;phenyl-l,3-dithiolan-2-yl... Do- 6 ,gi tliimethyla-phenylbenz- 12 Do. iiiiififfiiiifflff??? 5.1111111111111'138555;: if3a111111111%%11:.... 57 Do.

1 Not assayed.

parallel and the results are expressed as the amount of cephaloridine destroyed (expressed as pig. destroyed by 1 ml. of cell suspension or organism) divided by the amount of analogue destroyed. Following this, mixtures of 250 pg/ml. analogue and 250 pg/ml. cephaloridine were tested to determine whether the presence of the analogue could protect cephaloridine from destruction by the B-lactamases of the same organisms. in this case, the results are expressed as the amount of cephaloridine destroyed, divided by the amount of cephaloridine destroyed in the presence of the analogue. Thus the larger the number in the table, the more stable the test substance (S) is to the enzymes, and inf. implies total resistance. The (B) compounds are designated with respect to formula (I) above.

The bacterial action of cephaloridine alone and in combination with the anti B-lactamase compounds, against E.cloacae and Pr. morgam' is shown in tables 2A and 2B. The tables show the amount of growth or percentage kill at various times when E. cloacae is exposed to 250 pg/ml. of the cephaloridine and the protecting substances separately, and when they are combined, at 125 g/ml. each. Similar experiments were shown with Pr. morgani, although with compound (B) R'=2,6- dichlorophenyl and 2,4,6-trimethoxyphenyl the concentrations used were 3i ug/ml. separately or 16 ugJml. of each when combined with cephaloridine. The M.I.C. cephaloridine against Pr. morgani NCTC 235 can vary between 500 pgJml. and 62 ng/ml.

TABLE 2A Table 3 shows a further series of results calculated on the same basis as Table but using different compounds.

The invention will now be illustrated by the following examples of pharmaceutical and veterinary compositions.

COMPOSITION l Medium/Long Acting Veterinary Cerate cephaloridine Sodium 3acetoxyrnethyl-7- (2' .6'-dimethoxybenzam ido ceph-3-em-4-carboxylate Method |oo.0 mg.

l00.0 mg.

Arachis Oil 95.0%

[The percentage of kill oi cephaloridine alone and in combination with the anti fl-lactamase compounds with E. cloacae] Conce/ntration in Compound B pg. ml. ol- Percentage kill at hours Cephalor- Protecting B It idine substance 1 3 5 250 Nil GrownX487. 2,6-dimethoxyphenyl Acetate. Nil 250 Gr0WnX307.

125 GroWnX26. 260 Nil GroWnX31. 2,4,6-trimetbylphenyl do Nil 250 GroWnX37.

125 126 99.984. 7 250 Nil GrownXLltM. 2,6-dichlor0phenyl .do Nil 260 V.g.

125 125 100. 260 Nil GrownXSl. 2,4,6-trimethoxyphenyl .do Nil 260 GrownX839.

' -s-= .x.s qw A- TABLE 2B I [The percentage kill 01' cephaloridine alone and in combination with the anti fl-lactamase compounds with Pr. moraanz] Concentration in #gJrnl. of Compound B Percentage kill at hours- Cephalo- Protecting R R. rldine substance 1 3 5 24 250 Nil GrownX3..- 94. 143 99. 950 2,6-dimethoxyphenyl Acetate. Nil 250 GroWnX4. Nil GroWnX23 125 126 GrownX3 99. 890 100 100 250 Nil 2,4,6-trimethyiphenyl do 6 B9 31 2,6-dichlorophenyl .do 31 2,4,6-trimethoxyphenyl do N l Visibly grown. k

TABLE 3 Compound B Enzyme source P99 NCTC 235 Amount Amount Compound A R 1 R 1 destroyed A/B destroyed A/B C eph alothin 360, 400 110, 600 Do... 2,4,6-trimethylphenyl- Acetate. 2, 400 120 922 Do 2,6-dichloropheny1 o 6, 200 69 Nil Infinity Cephaloglycin. 21, 200 8, 300 Do 2,4,6-trimethylphenyl. Acetate. 7 30 Nil Infinity Do 2,6-dichlor0phenyl d0 1 Nil Infinity N-7-(2-thienylacetamido- 2,6 dimeth0xyphcnyl do 267 Infinity ceph-3-em-3-ylmethy1 carbamoylpyridinimn+ carboxylate. 4"-carbamoyl analogue of do do Infinity previous compound.

shear) stirrer and finally passed through a stainless steel-faced colloid mill before aseptically filling into sterile tubes.

COMPOSITION 2 Quick Release Veterinary Cerate Cephaloridine 100.0 mg. Sodium 3-acctoxymcthyl-7- (2.6-dimcthoxybenzamido)- ceph-3-em-4'carboxylate 100.0 mg. Tween 80 2.75%

White Beeswax 5.00% to 3.0 g. Arachis Oil 92.25%

Method 1. Heat the beeswax and arachis oil together to give a solution and strain through a stainless steel mesh.

2. Add the Tween 80.

3. Close the vessel to exclude micro-organisms and hold at 150 C. with stirring for 1 hr.

4. Cool rapidly with stirring to room temperature.

5. Then process as for Composition 1.

COMPOSITION 3 Injection A sterile dry powder mixture of Cephaloridine 500.0 mg. Sodium 3-acctoxyrncthyl-7- (2,6-dimethoxybenzamidol ceph-3-cm-4 carboxylate 500.0 mg.

to which 2.0 ml. of sterile water is to be added before injection.

Method 1. Weigh the two antibiotics into a sterile blender.

2. Blend.

3. Fill aseptically into sterile vials.

There will now be described the preparation of new compounds according to the invention.

These examples are given by way of illustration only.

Unless otherwise stated ultraviolet spectra are for solutions in 0.1 M phosphate buffer at pH 6.0; m.pts. were determined on a Kofler hot-stage microscope and optical rotations are for ca. 1 percent solutions in dioxan.

EXAMPLE 1 3-Acetoxymethyl-7-(5'-methyl-3'-phenylisoxazole-4-carbonamido)-ceph-3-em-4-carboxylic acid Ethyl-5-methyl-3-phenylisoxazole-4-carboxylate (prepared from a-chlorobenzaldoxime) was saponified to give S-methyl- 3-phenylisoxazone-4-carboxylic acid as colorless crystals m.p. 190-19l from ethanol.

5-Methyl-3-phenylisoxazole-4-carboxylic acid (3.75 g. 18.5 m. mole) was boiled under reflux with excess thionyl chloride (25 ml.) for 2 hr. and the thionyl chloride boiled off under reduced pressure to leave the acid chloride as an oil. This oil was dissolved in dry acetone (25 ml.) and added to a cooled stirred solution of 3-acetoxymethyl-7-aminoceph-3-em- 4-carboxylic acid (5.0 g. 18.4 m. mole), sodium bicarbonate (3.75 g. 45 m. mole), acetone (50 ml.) and water (75 ml); stirring and cooling were continued for 1 hr., after which the reaction was allowed to warm to ambient temperature over I hr. On completion, the acetone was removed under reduced pressure and the aqueous residue washed with diethyl ether (2X50 ml.), acidified to pH 1.5 and extracted with ethyl acetate (2X75 ml.). The bulked ethyl acetate extract was washed with water, dried and distilled to dryness under reduced pressure to leave a solid (6.0 g.) which was reprecipitated from acetone/b.p. 60-80 petroleum to give 3- acetoxy-methyl-7-( -methyl-3'-phenylisoxazole-4'-carbonamido)-ceph-3-em-4-carboxylic acid. Yield 5.8 g. (69.1 percent). R,Butano1system=0.73.

EXAMPLE 2 3-Azidomethyl-7-(5'-methyl-3-phenylisoxazole-4'-carbonamido)-ceph-3-em-4-carboxylic acid 3-Acetoxymethy1-7-( 5 '-methyl-3 -phenylisoxazole-4 -carbonamido)-ceph-3-em-4-carboxylic acid (1.0 g. 2.2 m. mole) was dissolved in water ml.) and sodium bicarbonate (0.184 g. 2.2 m. mole); the carbon dioxide was removed under reduced pressure, sodium azide (0.29 g. 4.4 m.mole) added and the solution heated in a closed flask at 50 for 17 hr. The reaction mixture was cooled, washed with ethyl acetate (3X20 ml.), acidified to pH 1.5 and extracted with ethyl acetate (3X25 ml.); the bulked extract was washed with water, dried and distilled to dryness under reduced pressure. The resultant glass was dissolved in ethyl acetate (50 ml.) and subjected to a diamond pattern separation using pH 5 phosphate buffer and ethyl acetate to give 3-azidomethyl-7-(5'-methyl-3'-phen- 0 X260 nm. inf. Ei?,,.,=250. R, ethyl acetate system=0.23, R, bu-

tanol system=0.81.

EXAMPLE 3 Sodium 3-acetoxymethyl-7-[3-(2"-chlorophenyl)-5'- methylisoxazole-4-carbonamido]-ceph-3-em-4-carboxylate 3-(2'-Chlorophenyl)-5-methylisoxazole-4-ylcarbonyl chloride (6.1 g., 24 m.moles) was dissolved in actone (40 ml.) and a portion (30 ml.) of this solution was added to a stirred solution of 3-acetoxymethyl-7-aminoceph-3-em-4-carboxylic acid (5.44 g., 20 m.moles) in water (200 ml.) and acetone (200 ml.) containing sodium hydrogen carbonate (4.2 g., 50 m.moles). After 15 min. the remainder of the acid chloride solution was added, and the reaction mixture was stirred for a further 30 min. The acetone was removed by evaporation at 30 and the aqueous layer was twice extracted into ethyl acetate. The resulting aqueous solution was acidified with 2N- hydrochloric acid and extracted three times with ethyl acetate ml.). The combined washed and dried extracts were evaporated to give a yellow foam (9.6 g.). This product in ethyl acetate 100 ml.) was treated with a 10 percent solution of sodium Z-ethyl-hexanoate in butan-l-ol (50 ml.) to give the title compound (8.9 g.), [a],,+62(c 0.88 in H O), Amax. (pH 6.0 phosphate buffer) 260 nm. (69000). A sample crystallized from acetone-ether water was analyzed (Found: C, 47.8; H, 3.7; CI, 6.6; N, 7.7; S, 6.1 C ,H,,C1NaN O S.H O requires C,47.4; H, 3.6; CI, 6.7; N, 7.9; S, 6.0%).

EXAMPLE 4 Sodium 3-azidomethyl-7-[ 3 2 '-chloropheny1 )-5 '-methylisoxazole-4'-carbonamido]ceph-3-em-4-carboxylate Replacement of the acetoxy group in sodium 3-acetoxymethyl 7-[ 3 2 '-chloropheny1)-5 '-methy1isoxazole-4'-carbonamido]ceph-3-em-4-carboxylate (example 3) by treating an aqueous solution with sodium azide as described in Pat. No. 1,012,943 gave sodium 3-azidomethyl-7-[3-(2"-ch1orophenyl)-5'-methylisoxazole-4-carbonamido]- ceph-3-em-4-carboxylate, max 260 nm. (5 7,300), vmax. (Nujol)2,110(N 1,760 (B-lactam), 1,660, 1,518 (CONH), 1,610 cm.- (CO EXAMPLES 5 and 6 Sodium 3-acetoxymethyl 7-[3'-(2", 6"-dich1orophenyl)-5'- methylisoxazole-4'-carbonamido]-ceph-3-em-4-carboxylate and sodium 3-azidomethyl-7-[3'-(2", 6"-dichloropheny1)-5- methylisoxazole-4'-carbonarnido]ceph-3-em-4 carboxylate In a similar manner to example 3 but starting from 3-(2', 6- dichlorophenyl)-5-methylisoxazol-4yl carbonyl chloride and (A) 3-acetoxymethy1-7-amino-ceph-3-em-4-carboxylic acid and (B) 7-amino-3-azidomethylceph-3-em-4-carboxylic acid, there were obtained (A) sodium 3-acetoxymethyl 7-[3-(2", 6"-dichlorophenyl)-5'-methylisoxazole-4'-carbonamido]- ceph-3-em-4-carboxylate, [(Xl 'i'76 (c 1.0 in H O), A max. (pH 6.0 phosphate buffer) 260 nm. (c8450) (Found: C, 45.6;

H, 3.1; CI, 12.9; N, 7.2; S, 5.4, C,,H,.;Cl NaN -,O-,S requires C, 46.0; H, 2.9; Cl, 12.9; N, 7.7; S, 5.8 percent) and (B) sodium 3-azidomethy1-7[3', 6"-dichlorophenyl)-5-methylisoxazole- 4'-carbon-amido]-ceph-3-em-4-carboxylate [a],,+ 73.5 (c 1.02 in H,O), A max. (pH 6.0 phosphate buffer) 260 nm. (e 9,300). (Found: C, 39.6; H, 2.5; Cl, 12.3; N, 14.8; S, 6.2. C,,H, Cl,NaN,O S, 2H,O requires C, 40.2; H, 3.0; C1, 12.5; N, 14.8; S, 5.7%).

EXAMPLE 7 3-Acetoxymethyl-7-( 5 '-methyl-3'-phenylisoxazol-4-ylacetamido)ceph-3-em-4-carboxylic acid a. 4-Diazomethylcarbonyl-5-methyl-3-phenylisoxazole 5- Methyl-3-phenylisoxazole-4-carboxylic acid (10.16 g., 50 m.moles) was heated under reflux in thionyl chloride (90 ml.) for 2 hr. Excess thionyl chloride was removed in vacuo to give 5-methyl-3-phenylisoxazole-4-carbonyl chloride (9.2 g., 84 percent) as a pale yellow solid melting at ca. room temperature.

The acid chloride (2.37 g., 10.8 m.moles) in dioxan (25 ml.) was slowly added to a solution of ethereal diazomethane 37.5 m.moles, prepared from nitrosomethylurea and assayed by reaction with an excess of p-nitrobenzoic acid) cooled to -2. The addition took 2 hr. after which the solution was allowed to warm to room temperature overnight. Excess diazomethane was still present. The reaction mixture was evaporated at 25 to give a pale yellow oil which was dissolved in ether and precipitated with light petroleum (b.p. 40-60) as a pale yellow solid diazoketone (1.07 g., 44 percent), m.p. 5758 (decomp.) A,,,,, (in ethanol) 227 (613,050) and 287 nm (10,000), v,,,,,, (CHBr at 2,120 (CHN 1,620 (ArCO) and 780, 768 cm. (Ph), p.m.r. (CDCl peaks at 2.48 (Ph), 4.98 (CH) and 7.28 r(CH b. -Methyl-3-phenylisoxazole-4-ylacetic acid i. Direct method by Wolff rearrangement of the diazoketone under aqueous conditions The diazoketone (4.88 g., 21.5 m.mole, total crude oil) was dissolved in dioxan (35 ml.) and slowly added to a warm (60-70) suspension of silver oxide (0.63 g.) in water (50 ml.) containing sodium thiosulphate (0.94 g., 6 m.moles) and sodium carbonate (1.58 g., 14.8 m.moles). The mixture was kept at 70 with stirring for 1 hr. when the temperature was raised to 100 for 0.5hr. The mixture was cooled, diluted with water (100 ml.), acidified with 2N-nitric acid and extracted into ethyl acetate (4X75 ml.). The organic layer was filtered through kieselguhr, washed twice with water and then with a saturated solution of sodium hydrogen carbonate (75 ml.) Most of the color remained in the ethyl acetate layer which was twice washed with water. The combined aqueous layers were acidified with 2N-hydrochloric acid to give a white precipitate which was extracted into ethyl acetate (3X75 ml.).

The washed and dried organic layer was evaporated to a yellow gum (3.6 g., 81 percent).

Attempts to crystallize the gum failed but on standing for Ca. 3 weeks some solidification occurred and recrystallization from ethyl acetate petroleum ether (b.p. 40-60) gave prisms, m.p. 79-8l, 230-232 nm (e 10,500), p.m.r. showed peaks at--0.32 (C0 14), 2.54 (Ph), 6.54 (CH,) and 7.59 1(CH (Found, for a sample after melting and resolidification: C, 65.9; H, 5.3; N, 6.5. C,,H,,NO,requires C, 66.3; H, 5.1; 6.45%).

ii. Via the ethyl ester The diazoketone (21.6 g., solvated, containing Ca. 80 m.moles) was dissolved in dry ethanol (900m1.) and warmed to 70. Part of a suspension of freshly prepared silver oxide (20 m.moles) in ethanol ml.) was added in portions ca. 0.5 ml.) over a period of 2.5 hr. at which time the ultraviolet spectrum of a suitably diluted sample of the reaction mixture indicated the absence of the diazoketone (no maximum at 288 nm). The black suspension was clarified by filtration through kieselguhr; the orange filtrate was evaporated to an orange oil. A solution of this oil in ethyl acetate (200 ml.) was washed successively with saturated sodium hydrogen carbonate (3x100 ml.), water (2Xl00 ml.) brine m1.) dried and evaporated to an oil (20.4 g.). Distillation at 1 mm. Hg. gave the ethyl ester in two fractions (6.4 g.), b.p. l70-l82 and (8.0 g.), b.p. 184, p.m.r. (CDCI peaks at 2.42 (Ph), 5.86 and 8.81 (CH CH 6.53 (CH and 7.53 -r(CH This ester (14.3 g., 58 m.moles) was saponified by treating an ethanolic solution ml.) with potassium hydroxide (6.0 g.) in water (20 ml.) at room temperature for 1.5 hr. Evaporation of the deep wine colored solution gave a red-brown oil which was shaken with water 100 ml.) and washed with ether (4X100 ml.). The aqueous layer was covered with ethyl acetate (100 ml.) and the pH of the mixture was dropped to 2 with concentrated hydrochloric acid. The aqueous layer was further extracted with ethyl acetate (3x100 ml.). The combined organic extracts were back-washed with water and brine, dried and evaporated to give a yellow oil which solidified 12 g.) when seeded with a trace of the required acid obtained as described above. Crystallization from ethyl acetate40-60 petroleum spirit gave 5-methyl-3-phenylisoxazol-4-ylacetic acid (7.1 g., 56 percent), m.p. 82, A, 234 nm (6 10,500) (Found: C, 66.6; 66.3; H, 5.4, 5.1; N, 6.1, 6.3. C l-l No requires C, 66.3; H, 5.1; N, 6.45%). Concentration of the mother liquors gave a second crop (2.2 g.) of less pure material.

c. 3-Acetoxymethyl-7-(5-methyl-3-phenylisoxazol-4'-ylacetamido )ceph-3-em-4-carboxylic acid The acid from (b) (2.8 g., 12.8 m.moles) was heated under reflux in thionyl chloride (25 ml.) for 1 hr. Excess reagent was removed by evaporation to give the acid chloride as a reddish oil (2.94 g.).

The acid chloride (assumed to be 12.5 m.moles) was dissolved in dry acetone (20 ml. A portion (15 ml.) of this solution was added dropwise to a cooled (10) solution of 7- aminocephalosporanic acid (2.72 g., 10 m.moles) in a mixture of acetone (100 ml.) and water (100 ml.) containing sodium hydrogen carbonate (2.1 g., 25 m.moles). After the addition was complete the reaction mixture was stirred for 15 min. and the remainder of the acid chloride solution (5 ml.) was added. The reaction mixture was removed from the cooling bath and allowed to stir at room temperature for 20 min. The pH (5.2) was adjusted to 7.0 and twice extracted with ethyl acetate to remove neutral products. The aqueous layer was covered with ethyl acetate ml.) and acidified with 2N-hydrochloric acid; further extraction with ethyl acetate (2Xl00 ml.) was carried out. The combined extracts were washed with water, dried and evaporated to a solid (2.42 g., 51 percent) which was recrystallized from ethyl acetate to give the title compound (1.09 g., 23 percent), m.p. l58-l60, [a],,+66 (c, 0.66 dioxan), 236 (15,600) and A260 nm (9,900), (Found for a sample dried at 40 in vacuo: C, 55.9; H, 4.8; N, 8.5; S, 6.5. C H ,N O-, S requires C, 56.0; H, 4.5; N, 8.9; S, 6.8%). A second crop (0.2 g.), m.p. l6l-163was obtained by concentrating the mother liquors.

EXAMPLE 8 3-Azidomethyl-7-(5-methyl-3'-phenylisoxazol-4'-ylacetamido)-ceph-3-em-4-carboxylic acid.

A solution of 7-amino-3-azidomethylceph-3-em-4- carboxylic acid (5.1 g., 20 m.moles) in acetone (150 ml.) and water (150 ml.) containing sodium hydrogen carbonate (4.2 g., 50 m.moles) was cooled to 10 and treated dropwise with a portion (9ml.) of a solution of the acid chloride (7.57 g., 25 m.moles) in acetone (12 ml.). After stirring for 15 min. the remainder of the acid chloride solution was added and the orange mixture was stirred at room temperature for 1 hr. The reaction mixture was worked up as described above to give the crude azide in three crops (3.7, 2.2 and 3.3 g., respectively) from ethyl acetate. These were treated separately with ether to remove residual side chain acid leaving a total of 6.4 g., 70 percent of the title compound, m.p. [a},,+75, A 235 nm (a 15,750) and A 262 nm. (e 9,500), (Found: C, 52.6;

52.6; H, 4.0, 4.0; N, 18.8, 18.8; s, 6.8. c,,H,,N,0,s requires C, 52.8; H, 4.0 N, 18.5; S, 7.05 percent).

EXAMPLE 9 3-Acetoxymethyl-7-l 3 2 '-chlorophenyl-5 -methylisoxazol-4-yl-acetamidolceph-3-em-4-carboxylic acid a. 3-(2'-Chlorophenyl)-4-diazomethylcarbonyl-5-methylisoxazole 3-(2-Chlorophenyl)-5-methylisoxazol-4-yl-carbonyl chloride (6.96 g., 27.2 m.moles) is dioxan (50 ml.) was slowly added to a solution of diazomethane (0.1 mole) in ether (360 ml.) at 10 to 5. The solutionwas allowed to warm to room temperature overnight. Evaporation left a solvated yellow oil nm.:z nm (EICM.4O6)1 'mru. (CHBrS) No attempt was made to purify this diazoketone.

b. 3-( 2'-Chlorophenyl)-5-methylisoxazol-4-yl-acetic acid The crude diazoketone (9.12 g., ca. 31.6 m.moles) was dissolved in warm, dry ethanol (200 ml.) and the yellow solution was heated to 70. An ethanolic suspension of freshly prepared silver oxide (from 20 ml. 0.5N-sodium hydroxide and 20 ml. 0.5N-silver nitrate in water followed by centrifuging the silver oxide, washing with three portions of ethanol and suspending in ml. dry ethanol) was added in ca. 0.5 ml. portions at 70. Nitrogen evolution was noted after addition of the catalyst, this soon stopped and more catalyst was added at half hour intervals for 5 hr. then at hourly intervals up to 7 hr. with heating under reflux. During this reaction ultraviolet spectra were run on filtered and suitably diluted samples (1 ml..-*..100 ml.) of the reaction mixture; the absorption at 287 nm due to the diazoketone was reduced from 1.16 to 0.71 (optical density units). A sample of the reaction mixture evaporated and examined by infrared spectroscopy, showed both a diazoketone band (2,120 cm. and a new ester band (1,735 cm."). Accordingly, the reaction mixture was retreated with frequent additions of fresh silver oxide under reflux until nitrogen was no longer evolved (3 hr. Ultraviolet and infrared spectra of a sample of the reaction mixtureshowed only a trace of the diazoketone remaining. The bulk of the reaction mixture was filtered through kieselguhr, the orange filtrate was evaporated to dryness in vacuo. The resulting brown oil in ethyl acetate (50 ml.) was washed (2X30 ml.). The organic layer was dried and evaporated to give the ethyl ester as a brown oil which was dried in vacuo and used without further purification (8.02 g., 91 percent).

The crude ethyl ester (8 g., 28.8 m.moles) was dissolved in ethanol (60 ml.) and treated with a solution of potassium hydroxide (3 g., ca. 45 m.moles) in water (10 ml.) to give a deep-red solution which was kept at room temperature for 1.5 hr. The mixture was then evaporated and the red-brown oil was shaken with water (100 ml.) and ether (100 ml.). The aqueous layer was further extracted with ether (2 l00 ml.); evaporation of the combined, dried ether extracts gave an orange-yellow oil (0.88 g.).

The aqueous layer was covered with ethyl acetate 100 ml.) and acidified to pH 1.5 with concentrated hydrochloric acid. The aqueous layer was further extracted with ethyl acetate (2X50 ml.). The deep-red extracts were combined, washed with water (2X30 ml. dried and evaporated to a dark-brown gum. This material was purified by three successive triturations with petroleum (b.p. 40-60) (100 ml.) containing ether (10 percent v./v.) to give the title acid as a buff crystalline solid (4.54 g., 63 percent), m.p. 98-99, p.m.r. (D 0 with sodium hydrogen carbonate) showed peaks at 2.50 (aromatic, 4H), 6.75 (CH and 7.53 (CH )1-(Found: C, 56.8, 57.4; H, 4.0, 4.0; N, 5.1, 5.4; Cl, 14.1. C H ClNO requires: C, 57.1; H, 4.0; N, 5.5; Cl, 14.1%). A second crop (0.63 g.). m.p. 98, was obtained as blades from the ether-petroleum triturates.

c. 3-Acetoxymethyl-7-l 3 2' '-Chlorophenyl)-5 '-methylisoxazol-4'-yl-acetamido]-3-em-4-carboxylic acid 3(2'-Chlorophenyl)-5-methylisoxazol-4-yl-acetic acid (2.2 g., 8.7 m.moles) was heated to reflux with thionyl chloride (25 ml.) for 1.5 hr. The solvent was evaporated and the resulting oil was kept at room temperature under high vacuum for 2 hr.

The crude acid chloride (2.45 g.) was dissolved in acetone (3ml.). A portion (2.5 ml.) of this solution was added to a cooled (10) and stirred solution of 7-aminocephalosporanic acid (1.9 g., 7 m.moles) in water (50 ml.) and acetone (50 ml.) and acetone (50 ml.) containing sodium hydrogen carbonate 1.47 g., 17.5 m.moles). The mixture was stirred for 15 min. when the remainder of the acid chloride was added. A solid was precipitated at this stage and the mixture was stirred for 1.75 hr. at room temperature. The pH (5.2) was adjusted to 7.0 with sodium hydrogen carbonate solution and the mixture was evaporated to remove acetone. Neutral products were extracted with ethyl acetate (3X50 ml.) and the aqueous layer was acidified with ZN-hydrochloric acid. Extraction into ethyl acetate (4X50 ml.) and evaporation of the washed and dried extracts yielded the crude product (3.88 g.), A,,,, 256 nm (Eiif l57). Paper chromatography supported by infrared and p.m.r. evidence showed evidence of contamination with the starting acid. The crude product was heated under reflux with ether (200 ml.) for 15 min.; filtration gave a solid (2.8 g.) free of such contamination. Recrystallization from ethyl acetate gave the title acid (1.42 g., 40 percent), [a] +46.5 A 257-260 nm (5 8,600), (Found: C, 52.05, 52.2; H, 4.1, 4.15; Cl, 7.1; N, 7.8, 7.85; S, 6.2. C, H, ClN O,S requires: C, 52.2; H, 4.0; Cl, 7.0; N, 8.3; S, 6.3 percent).

EXAMPLE l0 3-Azidomethyl-7-[ 3 2-chlorophenyl )-5 -methyl-isoxazol- 4'-yl-acetamido]ceph-3-em-4-carboxylic acid 7-Amino-3-azidomethylceph-3-em-4-carboxylic acid (2.55 g., 10 m.moles) was dissolved in acetone (50 ml.) and water (50 ml.) containing sodium hydrogen carbonate (2.1 g., 25 m.moles). The resulting pale yellow solution was treated with part (2.5 ml.) of a solution of 3-(2-chlorophenyl)-5- methylisoxazol-4-yl-acetyl chloride (2.33 g., 8.6 m.moles) in acetone (3 ml.). The light brown solution was stirred for 15 min. and then the remainder of the acid chloride solution was added. The mixture was stirred at room temperature for 1 hr. and then extracted into ethyl acetate (3X50 ml.). The aqueous layer was covered with ethyl acetate and acidified to pH 1.5 with concentrated hydrochloric acid. Some solid, insoluble in both layers was removed by centrifuging, the aqueous layer was further extracted into ethyl acetate, the combined extracts were washed with water, and evaporated to give a solid (1.63 g.). This product was boiled with ether (50 ml.) for 15 min.; the ether was decanted and the gummy solid was dissolved in acetone (20 ml.), filtered, and the filtrate treated with water (50 ml.) with warming. The clear solution deposited crystals at 5 overnight; these were collected and dried in vacuo over phosphorous pentoxide to give the title acid (0.32 g.), m.p. 154 (decomp.) [a],,+62, A 260 nm. (6 8,700), (Found: C, 47.8, 48.0; H, 3.6, 3.6; Cl, 7.5; N, 16.3, 16.3, 16.4; S, 6.7. C ,,H,,ClN O S, 0.51 1 0 requires C, 48.2; H, 3.6; Cl, 7.1; N, 16.9; S, 6.4 percent). Two further crops (0.24 and 0.037 g.) were obtained from the mother liquors and a fourth crop (0.4 g.) from the ether extract bringing the total yi ld F liilps ss EXAMPLE 1 l a. 3-(2', 6'-Dichlorophenyl)-4-diazomethylcarbonyl-5- methylisoxazole 3-( 2' 6'-Dichlorophenyl )-5-methylisoxazole-4-carbonyl chloride (6.57 g., 22.4 m.moles) in dry dioxan (25 ml.) was added to a stirred solution of diazomethane (62 m.moles) in ether (186 ml.) with cooling to between l0 and 0. The cloudy yellow solution was allowed to warm to room temperature and stand overnight. The solvents were removed at 40 to give the diazoketone as a pale yellow crystalline solid (5.16 g., 78 percent), X 286-287 nm (too insoluble in ethanol to get accurate absorbance figures), v,,,,, (CHBr 2,120 (N and 1,618 cm. (COC=C-).

b. 3-(2', 6-Dichlorophenyl)-5-methylisoxazol-4-yl-acetic acid The diazoketone from (a) (5.16 g., 17.5 m.moles) was dissolved in warm dry ethanol (200 ml.). An aliquot (0.1 ml.) of

this solution was diluted to 100 ml. with absolute ethanol and the ultraviolet spectra recorded (A,,,,,, 287 nm, optical density 1.00). The bulk of the solution was placed in a thermostat bath at 70 and treated with a portion Ca. 1 ml. of a suspension of freshly precipitated silver oxide (2.32 g.) in dry ethanol 10 ml.). The flask was swirled and after a few minutes evolution of nitrogen was observed. A further aliquot of silver oxide was added and the reaction mixture was left at 70 for 30 min. when gas evolution had stopped. A third portion of silver oxide suspension was then added with shaking. After a total time of 1 hr. an aliquot was diluted and submitted for an ultraviolet spectrum (X 286 nm, optical density 0.79). The procedure was repeated, additions of silver oxide suspension being added at 30 min. intervals. After 3 hr. a diluted aliquot showed an optical density of 0.22 at 280 nm; this decreased to 0.08 (note: during the last 1 hr. the reaction mixture was heated under reflux.) The cooled mixture was filtered through kieselguhr and evaporated at 40 to a dark yellow oil which was dissolved in ethyl acetate and washed successively with a saturated solution of sodium bicarbonate and water. The dry extract was evaporated to give the ethyl ester as a yellow viscous oil (4.6 g.

The ethyl ester (4.6 g.) was dissolved in dry ethanol (50 ml.) and a solution of potassium hydroxide (2g.) in water (6 ml.) was added. The deep red solution was allowed to stand at room temperature for 1.5 hr.; a yellow solid was deposited on the sides of the flask during this time. The reaction mixture was evaporated at 30 and the red oil was shaken with water 100 ml.) and extracted into ether (3X50 m1. Evaporation of these extracts gave a yellow oil (0.87 g.) which was not further examined. The red aqueous layer was covered with ethyl acetate and acidified with concentrated hydrochloric acid to pH 1.6. The layers were separated and the aqueous layer was further extracted with ethyl acetate (2X50 ml.). The combined extracts were washed with water, dried and evaporated to give a brown solid (3.07 g.). Crystallization from aqueous ethanol gave two crops of crystals (0.97 g., m.p. l72l73 and 0.62 g., m.p. l68-l70) and a residue as a pale yellow solid weighing 1.06 g. Total yield 63 percent. The first crop was recrystallized from aqueous acetone to give the title acid as yellow needles mp. 170, A 273-274 nm (e 715) and inflections at 238 nm (5 5,380) and 280 nm (6620), (Found: C, 50.2; H, 3.3; Cl, 24.8; N, 4.7. c gHgclzNoa requires: C, 50.3; H, 3.2; C], 24.8; N, 4.9%).

c. The dichloroacid from (b) (1.9 g.) was heated under reflux with thionyl chloride (25 ml.) for 1.5 hr. and evaporated to give the crude acid chloride (2.2 g., 100 percent) as a brown gum. This material in acetone (3 ml.) was divided into two parts the larger of which (2.5 ml.) was added dropwise to a cooled stirred solution of 7-aminocephalosporanic acid (1.57 g., 5.8 m.moles) in water (50 ml.) containing sodium hydrogen carbonate (1.32 g., 15.7 m.moles). The mixture was stirred for min. when the remainder of the acid chloride solution was added and stirring continued for 1.75 hr. at room temperature. The pH was adjusted to 7.0 with ethyl acetate (3X50 ml. The aqueous layer under ethyl acetate (50 ml.) was acidified to pH 1.5 with 2N- hydrochloric acid and some 7-aminocephalosporanic acid (0.24 g.) was filtered off. The aqueous layer was further extracted into ethyl acetate and the extracts were combined, washed with water, dried and evaporated to give an orange solid (0.79 g.). This product (0.70 g.) in ethyl acetate ml.) was treated with sodium ethyl hexanoate in butan-lol (5 ml., 10 percent w/v. solution) to give a pale yellow gelatinous solid which was collected and dried to provide (0.46 g.), [a],,+71.5 (water) A 260 nm (e 8,500) (Found: C, 47.7, 47.3; H, 4.0, 3.7; N, 6.7, 6.4. C H ChNaN O S, 0.5 EtOAc requires: C, 47.5; H, 3.7; N, 6.9%) of sodium 3-acetoxymethy1-7-[3'-(2 III! EXAMPLE l2 3-Azidomethyl-7-[ 3 2' '-dichlorophenyl)-5 '-methylisoxazol-4-yl-acetamido]ceph-3-em-4-carboxylic acid 7-Amino-3-azidomethylceph-3-em-4-carboxy1ic acid (2.12 g., 8.3 m.moles) was acylated with crude acid chloride obtained from 3-(2',6'-dichlorophenyl)-5-methylisoxazol-4-ylacetic acid (2.4 g., 8.3 m.moles) as described above. Workup resulted in recovery of the starting azide (0.39 g.) and an ethyl acetate soluble solid 1.98 g.) which could not be satisfactorily crystallized. The product was dissolved in ethyl acetate (200 ml.) and treated with sodium 2-ethyl hexanoate in butanlol (10 ml., 10 percent w./v.). No solid precipitated so the solution was slowly poured into ether (500 ml.), cooled at 5 for several hours and centrifuged to give the sodium salt of the title compound (0.59 g., 13 percent A, 264 nm (8,350), (Found: C, 42.5; H, 3.6; Cl, 12.2; N, 12.6; S, 5.8. C H CI 1-:=.\1-1.,o,,,, 0 requires C, 42.6; H, 3.1; Cl, 12.6; N, 14.9; S, 5.7%) characterized by a single spot on chromatography.

EXAMPLE l3 EXAMPLE 14 3-Acetoxy-7-(o-methylmercaptobenzamido)-ceph-3-em-4- carboxylic acid o-Methylmercaptobenzoic acid (2.25 g. 13.4 m.moles) was converted to its acid chloride with thionyl chloride. Reaction with 3-acetoxy-methyl-7-aminoceph-3-em-4-carboxylic acid (3.0 g. 11 m.moles under conditions outlined in example 1, gave the title compound Yield 4.0 g. (86.0 percent). A 258 nm max. 5}35346. R, butanol system 0.77, R, ethyl acetate system 0.18.

EXAMPLE 15 a 2 -Carboxy-2 -phenyl-l,3 -dithiane' A solution of 2 phenyl-1,3 -dithiane (19.63 g., 0.1 mole) in dry tetrahydrofuran ml.) at -30 C. under nitrogen was stirred and treated with two equivalents of n-butyl-lithium in ether (100 ml.) over a period of 30 minutes. The mixture was stirred at 30 C. for a further 30 minutes then cooled to 70 C. and treated at this temperature with a rapid stream of dry, oxygenfree, carbon dioxide gas for 2 hour. The reaction mixture was allowed to warm to 0 C., then poured into ice-water (300 ml.), separated, and the aqueous phase washed with ether (100 ml.). The organic phase and ether washings were extracted with 3 percent -sodium hydrogen carbonate (100 m1. and the combined aqueous portion acidified to pH 2.5 under ether ml.). The aqueous portion was reextracted with ether (100 ml.), and the combined extract washed with water (100 ml.), dried, and concentrated in vacuo to give a white crystalline solid (19.5 g., 81 percent) which crystallized from benzene-ether(2 1 to give 2 -carboxy-2 -phenyl-1,3 -dithiane as needles (16.5 g., 69 percent), m.p. 144-l47, v,,,,, (nujol) 2,600 and 1,686 (-CO H), 715 and 690 emf. (C H, Found: C, 54.9; H, 5.1; S,26.8 C, H 0 S requires C, 55.0 H, 5.0; S, 26.7 percent).

b. 2 -Chlorocarbonyl -2 -phenyl-1,3 -diethiane 2 -Carboxy-2 -phenyl-1,3 -dithiane (4.81 g., 20 m.moles), benzene (20 ml.) and thionyl chloride (2.9 ml., 40 m.moles) were heated together under reflux for 1 hr. Volatile material was removed under reduced pressure, leaving a solid product which crystallized from light petroleum (b.p. 6080) to provide 2 chlorocarbonyl-2 -phenyl-1,3 -dithiane as pale-brown prisms (4.1 g., 79 percent), m.p. 8790, u,,,,,, (CHBr;, 1,780 (-COCl), and 700 cm. (C,, H, (Found: C 51.1;H, 4.15; Cl, 13.6; S, 24.4. C H C108 requires C, 51.0; H, 4.3; CI, 13.7;S, 24.8 percent).

c. Sodium 3 -azidomethyl-7 -(2-phenyl-l,3 -dithiane-2'- carboxamido) ceph-3 -em-4 -carboxylate.

7 -Amino-3 -azidomethylceph-3 -em-4 -ca.rboxylic acid (2.55 g., 10 m.moles) was dissolved in solution of sodium hydrogen carbonate (2.1 g., 25 m.moles) in water (40 ml.), and acetone (30 ml.) was added. The stirred solution was cooled to -5 C and treated with a solution of 2 -ch1orocary -p s 313 13 31152ia j fill fll 3.99% (16 ml.) over a period of 2 min. The mixture was stirred at 0- C for 15 minutes then a further quantity of the acid chloride (0.65 g., 2.5 m.moles) in acetone (4 ml.) was added. The reaction mixture was allowed to reach room temperature over 1 hour, filtered and concentrated in vacuo to remove the bulk of the acetone. The resulting solution was washed with ethyl acetate (2 X50 ml.) and upon cooling the title compound was deposited as a white solid (3.1 g., 62 percent). Recrystallization from water afforded a purified product (1.8 g., 36 percent), (a) +67 (c 1.03; dimethyl sulfoxide), A 260-261 nm, (9,040 v,,,,,,. (nujol) 2,110 (--N;,), 1,760 (B-lactam), 1,680 and 1,500 (amide), 1,610 (C0 750 and 693cm. (C H (Found, a 45.65; H, 3.6; N, 13.35; Na, 4.2; S, 18.3. C H N NaO S requires C, 45.7; H, 3.6; N, 14.05; Na, 4.6; S, 19.3 percent). R,-0.64, R 4.57 (system A); R,-0.77, R 1.10 (system B).

Acidification of the original aqueous filtrate to pH 2.0, followed by ethyl acetate extraction (1x100 ml., 2X50 m1.) gave, after washing the extract with water (50 ml.) drying, and evaporation in vacuo, the free acid of the title compound as a crude yellow foam 1.5 g., 31 percent).

EXAMPLE 16 a. Z-Ethoxycarbonyl-Z-phenyl-1 ,3-dithiolane A solution of ethylbenzoylformate (25.0 g., 0.15 moles) in a mixture of benzene (250 ml.) and l,2-ethanedithiol (13.0 ml., 0.155 moles) containing p-toluenesulfonic acid (2.7 g., 0.015 moles) was heated under reflux in a Dean-Stark water separator for 18 hr. The bulk of the benzene was removed by distillation and the resulting solution poured into water (200 ml.), separated, then successively washed with saturated aqueous sodium carbonate (100 ml.), water (100 ml.), dried, and evaporated in vacuo to leave a white solid (27.7 g., 78 percent). This material crystallized from light petroleum (b.p. 60-80)-ether to furnish 2-et hoxycarbonyl-2-phenyl-l,3- dithiolane as prisms 16.7 g., 47 percent), m.p. 54-58, v,,,,, (CS 1,725 and 1,200 (ester), 725 and 688 cm.(C l-l A further crystallization provided the analytical sample, m.p. 58- 58.5". (Found: C, 56.6; H, 5.15; S, 24.8. C l-1 ,0 8 requires C, 56.55; H, 5.55; S, 25.2 percent).

b. 2-Carboxy-2-phenyl-1,3-dithiolane A suspension of 2-ethoxycarbonyl-2-phenyl-1,3-dithiolane (16.0 g., 63 m.moles) in 0.5 N-aqueous-alcoholic potassium hydroxide solution (1:1) (200 ml.) under nitrogen was stirred at room temperature for 1 hr. and then under reflux for a further 1 hr. The bulk of the ethanol was removed from the resulting solution in vacuo and the aqueous residue diluted with water (100 ml.) and washed with ether (2X50 ml.). The aqueous solution was acidified to pH 3.0 H, under ether (100 28.3 percent). the aqueous portion was reextracted with ether (2X50 ml.). Evaporation of the dried extract in vacuo gave 2- carboxy-Z-phenyl-l,3-dithiolane which crystallized from benzene-ether in needles (1 1.8 g., 83 percent), m.p. l64-l65 v,,,,,, (nujol) 2,600 and 1,700 (-CO H), 722 and 698 cm."

c, 53.1JR4TZS; s, 2813 imam;

c. 2-Chlorocarbonyl-2-phenyl-1 ,3-dithiolane l 8 2-Carboxy-2-phenyl-1,3-dithiolane (4.52 g., 20 m.moles), benzene (20 ml.) and thionyl chloride (2.9 ml., 40 m.moles) were heated together under reflux for 1 hr. Volatile material was removed under reduced pressure leaving a pink solid which crystallized from light petroleum (b.p. 6080)-ether to provide 2-chlorocarbonyl-2-phenyl -1,3-dithiolane as white needles (3.6 g., 73.5 percent), m.p. 57-60, u (nujol) 1,790 and 1,775 (COC1) and 710 cm. C,,H,- (Found: C, 49.0; H, 3.6; C], 14.0; S, 26.1. c,,rr,clo,s requires C, 49.1; H, 3.7; C1, 14.5; S, 26.2 percent).

d. Sodium 3-azidomethyl-7-(2-phenyl-1', 3-dithiolane -2'- carboxarnido) ceph-3-em-4-carboxylate 7-Amino-3-azidomethyl-3-em-4carboxylic acid (2.55 g., 10 m.moles) was dissolved in a solution of sodium hydrogen carbonate (2.1 g., 25 m.moles) in water (40 ml.), and acetone (30 ml.) was added. To the stirred solution at 0-5 C. was added a solution of 2-chlorocarbonyl'2-phenyl-1,3-dithiolane (2.45 g., 10 m.moles) in acetone (16 ml.) over a period of 2 .min. Immediately precipitation occurred. The mixture was stirred at 0-5 C. for 15 min., then a further quantity of the acid chloride (0.61 g., 2.5 m.moles) in acetone (4 ml.) was added. The reaction mixture was allowed to reach room temperature over 1 hr. and the solid product was collected (3.4 g., 70 percent). Concentration of the filtrate provided a second crop of similar material (0.75 g., 15 percent). Recrystallization of the combined crops from water provided the title compound as a white solid (2.74 g., 56.5 percent), (a) D l-725 (c 1.0; dimethyl sulfoxide), X 261 nm (6 9,550), v,,,,,, (nujol) 2,108 (N 1,754 (B-lactam), 1,675 and 1,502 (amide) and 1,604 cm. (CO (Found: C, 43.6; H, 3.5; N, 13.75; Na, 4.5; S, 19.6. C, H, N -,NaO S requires C, 44.5; H, 3.3; N, 14.4; Na, 4.7; S, 19.8 percent). R 0.54; R 3.85 (system A);

'R 0.77; R 1.10 (system B).

EXAMPLE 17 a. 2-Ethoxycarbonyl-6,7-dimethyl-2-phenylbenz(e)-l ,3- dithiepen A solution of ethyl benzoylforrnate (4.45 g., 25 m.moles) in benzene (75 ml.) containing l,2-dimethyl-4,5-di(mercaptomethyl) benzene (4.95 g., 25 m.moles) and p-toluenesulfonic acid (0.47 g., 2.5 m.moles) was heated under reflux in a Dean-Stark water separator for 17 hr. The cooled solution was poured into water (75 ml.) and the organic layer was separated, washed with saturated aqueous sodium hydrogen carbonate (50 ml.), and dried. Removal of the solvent in vacuo afforded a white solid which crystallized from light petroleum-ether to provide the title ester (3.78 g., percent) as prisms m.p. ll61l6.5, v,,,,,, (CS 1,720 and 1,208 CO C H 722 and 688 cm. (C H,,). (Found: C, 66.3; H, 6.2; S, 17.8. C ,,H O S requires C, 67.0; H, 6.2; S, 17.9 percent).

b. 2-Carboxy-6,7-dimethyl-2-phenylbenz(e)-l ,3-dithiepen A suspension of 2-ethoxycarbonyl-6,7-dimethyl-2-phenylbenz(e)-l,3-dithiepen (3.7 g., 10.3 m.moles) in 0.5 N-aqueous alcoholic potassium hydroxide solution (1:1) (50 ml.) under nitrogen, was brought gently to reflux. After 30 min. the reaction mixture, which had turned a deep blue color, was cooled to 0-5, whereupon the crude sodium salt of the title compound was deposited as a pale blue crystalline solid (3.5 g., 99 percent). This material was suspended in water (200 .ml.), washed with chloroform (2x100 ml.), and acidified to pH 2.5 under ether (100 ml.). The aqueous portion was reextracted with ether (2X50 ml.) and the combined extract was washed with water (50 ml.), dried and concentrated in vacuo leaving a white solid (2.6 g., 77 percent) which crystallized from benzene-ether to give the title acid as prisms (2.29 g., 67 percent), m.p. l92.5194. A portion of this material was recrystallized to give an analytical sample, m.p. l96-l97, v,,,,, (nujol) 1,685 cm. (CO H). (Found: C, 64.35; H, 5.5; S, 19.0. C H O S requires C, 65.4; H, 5.5; S, 19.4 percent).

c. 2-Chlorocarbonyl-6,7-dimethyl-2-phenylbenz(e)-1,3- dithiepen 2-Carboxy-6,7-dimethyl-2-phenyl-benz(e )-l ,3-dithiepen ,CmH ClSO: requires C, 6 1.95; H, 4.9; Ci, 10.2; S, 18.4).

d. Sodium a-azidoTnem l-ili", "l -tii'iiletT t'z shnyi benz(e )-l 3 '-dithiepen-2'-carboxamido)ceph-3-em-4-carboxylate 7-Amino-3-azidomethylceph-3-em-4-carboxylic acid (0.66 g., 2.58 m.moles) was dissolved in a solution of sodium hydrogen carbonate (0.54 g., 6.44 m.moles) in water (10 ml.) and acetone (10 ml.) was added. To the stirred solution at 5 was added a solution of 2-chlorocarbonyl-6,7-dimethyl- 2-phenylbenz(e)-1,3-dithiepen (0.90 g., 2.58 m.moles) in acetone (25 ml.) over a period of 2 min. The mixture was stirred at 5 C. for 15 min., then a further quantity of the acid chloride (0.20 g., 0.6 m.moles) in acetone (10 ml.) was added. The reaction mixture was allowed to reach room temperature over one-half hr. and then concentrated under reduced pressure, filtered, diluted with water (300 ml.) and washed with ethyl acetate 100 ml.). The aqueous portion was acidified to pH 2.5 under ethyl acetate (100 m1.), separated and reextracted with further ethyl acetate (2X50 m1. The organic extract was washed with water (50 ml.), dried, and the solvent evaporated off in vacuo leaving a yellow foam (0.94 g., 64 percent). This foam was dissolved in acetone ml.) and treated with percent sodium 2-ethylhexanoate in acetone (3 ml.). The title compound was precipitated from this solution by the addition of excess ether as an off-white solid (0.75 g., 49 percent), (a)D+59.4 (c 1.03; water) X 260 nm. (9,200), v,,,,,,. (nujol) 3,350, 1,682 and 1,500 (amide), 2,112 (azide), 1,765 and 1,755 (fl-lactam) and 1,610 cm. (CO,) (Found: C, 52.7; H, 4.3; N, 9.8; S, 15.6. C ,,l-l N NaO S, requires C, 52.95; H, 4.1; N, 11.9; S, 16.3 percent). R,-0.65, R, 5.91 (system A).

EXAMPLE 18 a. DL-2-Phenyl-2-acetoxypropionic acid DL-2-Phenylacetic acid (9.24 g., 0.055 mole) and acetyl chloride 18.5 ml.) were heated together at 6080 for 1% hr. Volatile material was removed in vacuo at less than 80 and the residue was stored for 2 days in a refrigerator with water (150 ml.). The colorless semisolid was extracted with ether (2x250 ml., 1x100 ml.), the ether extracts were washed with water (3X50 m1.), dried over magnesium sulfate, and evaporated in vacuo. The semisolid residue (10.18 g.) was warmed with water (50 ml.), cooled to room temperature, and stirred vigorously for several hours; after being refrigerated for 1% hours, the crude crystalline product (8.92 g.) was collected and dried in vacuo. A portion (1.03 g.) was crystallized from di-isopropyl ether (3 ml.) to give colorless needles (159 mg.) showing anhydride bands in the infrared spectrum; a second crystalline crop (384 mg.), free from anhydride bands in the infrared region, was obtained on concentration of the liquors. Recrystallization of the second crop gave DL-2-phenyl-2-acetoxypropionic acid, colorless needle-clusters from cyclohexane (328 mg), mp. 106-l08, v (nujol) 2,650, 2,540, 1,710 (CO,H), 1,740 and 1,222 (acetate) emf; 1(deuterium oxide+sodium bicarbonate) 7.82 (COCH and 8.1 1

1,828 and 1,753 (anhydride), 1,745 and 1,039 (acetate) and 20. 689 (phenyl) emf; r(deuteriochloroform) singlets at 2.62 (phenyl), 8.32

was

and 8.16 (COCH (Found: C, 66.6, 66.0; H, 5.6, 5.7. C H 0 requires C, 66.3; H, 5.6%).

b. DL-Z-Phenyl-2-acetoxypropionyl chloride A solution of DL-2-phenyl-2-acetoxypropionic acid (7.83 g., 0.0376 mole) in dry benzene (50 ml.) was treated with thionyl chloride (7.8 m1.) and the mixture was refluxed for 1% hr. Volatile material was removed under reduced under pressure and the product was distilled to give DL-2-phenyl-2- acetoxypropionyl chloride as a colorless oil (4.93 g., 58%), b.p. 114/0.9 mm., n D 1.5138; A, (carbon disulflde) 1,792 (COCl), 1,760 and 1,220 (acetate) emf 'r(deuteriochloroform) 7.72 (CO'CH and 8.00

SZSCEE F p.p.m.

C. 3-Azidomethyl-7-( DL-2-phenyl-2-acetoxypropionamido) ceph-3-em-4-carboxylic acid A suspension of 3-azidomethyl-7-aminoceph-3-em-4-carboxylic acid (5.00 g., 0.0196 mole) in boiling ethyl acetate (200 ml.) was treated with DL-2-phenyl-2-acetoxypropionyl chloride (4.49 g., 0.198 mole), and the mixture was refluxed for 1 hour. Solid material (3.4 g.) was removed by filtration of the cooled reaction mixture, and the filtrate was treated with aniline (5.36 ml.) and kept for 1 hr. The mixture was extracted with 3 percent sodium hydrogen carbonate solution (3X 100 ml.), the combined aqueous extracts were washed with ethyl acetate (3x100 ml.), and then acidified to pH 1.5 with stirring under ethyl acetate (100 ml.), using 2N- hydrochloric acid. The aqueous phase was then further extracted with ethyl acetate (2x100 ml.), the combined organic extracts were washed with water (2X50 ml. stirred with charcoal, dried over magnesium sulfate, and evaporated in vacuo at room temperature to give a yellow foam (5.17 g.). A portion (3.32 g.) of this acidic fraction was dissolved in chloroform (15 ml.) and the solution was poured into petrol (b.p. 40-60) (650 ml.) and the mixture was stirred; the precipitated solid (2.60 g.) was collected, washed with petrol and dried in vacuo. This material was reprecipitated from chlorofonn (15 ml.) with di-isopropyl ether ml.) to give an amorphous pale yellow solid (756 mg.), the title cephalosporin derivative contaminated with a little DL-2- phenyl-2-acetoxypropionic acid and di-isopropyl ether, revealed by paper chromatography and proton-magnetic resonance spectroscopy (18.84 and 8.94 p.p.m. respectively. [a],,+43 (c 1.0, dioxan), A 261 nm. (e 7,850), v,,,,,, (nujol) 2,1 10(azide) 1,772 (B-lactam) 1,730 and 1,220 (acetate), 1,690 and 1,520 (amide) cm 'i-(deuterium oxide-lsodium bicarbonate) singlets at 7.78 (CO-CH 8.05

EXAMPLE 19 Sodium 3-acetoxymethyl-7-(2,4,6-trimethyl-benzamido)- ceph-3-em-4-carboxylate 7-Aminocephalosporanic acid (1.5 g.) was suspended in a mixture of hexamethyldisilazane (2.2 g.) and chloroform 15 ml., dried by passing through basic, grade 1, WOELM Alumina) and the mixture refluxed for 45 min. The chloroform and the excess of hexamethyldisilazane were removed in vacuo, leaving a light brown gum. This material was dissolved in ethyl acetate (45 ml., dried by passing through neutral,

grade 1, WOELM Alumina) and 2,4,6-trimethy1ben7oyl chloride (1.0 g.) was added. The solution was boiled under reflux for 1 hr., cooled and treated with aniline to neutralize excess acid chloride. After 1 hr., the mixture was extracted with 3 percent sodium bicarbonate solution. This extract was washed with ethyl acetate and then acidified to pH 1.5 with concentrated hydrochloric acid, in the presence of ethyl acetate. The aqueous layer was separated and extracted with ethyl acetate. The combined ethyl acetate extracts were washed with water and then dried over magnesium sulfate The solvent was removed in vacuo, and the resulting yellow froth dissolved in acetone and treated with 10 percent sodium 2- ethylhexanoate in acetone. After standing for 1 hr. at room temperature, the sodium salt was filtered off and washed with acetone and ether. The buff solid was dried in vacuo over phosphorous pentoxide (yield 1.31 g., 54%). This material crystallized from aqueous acetone as colorless needles, [or] D+59 (C, 1.0; H 11 260 mp. (9,900), v,,,,,, (Nujol) 1,765 (B-lactam), 1,725 and 1,250 (OCOCH 1,640 and 1,530 (CONH), 1,622 (COC') cm. (Found: C, 54.3; H, 4.8; N, 6.3; S, 7.1. C H N NaO S requires C, 54.5; H, 4.8; N, 6.4; S, 7.3%).

EXAMPLE 20 Sodium 3-azidomethyl-7-(2, 4, 6'-trimethyl-benzamido)- ceph-3em-4-carboxylate By using the general method of example 19, but with 3- azidomethyl-7-aminoceph-3-em-4-oic acid (2 g., 7.9 m.moles), hexamethyldisilazane (2 g., 12.4 m.moles) and 2,4,6-trimethyl-benzoyl chloride (1.5 g., 8.2 m.moles), sodium 3-azidomethyl-7-(2, 4', 6'-trimethylbenzamido)-ceph-3- em-4-carboxylate was obtained as a buff solid (1.96 g., 59%). This material crystallized from aqueous acetone as colorless needles, [a]D +67.4, (C, 1; H O), A 260 my. (6 9,400), u (Nujol) 2,120 (-N;,), 1,770 (B-lactam), 1,650 and 1,522 (CONH), 1,620 (COO) emf (Found: C, 51.5; H, 4.2; N, 16.8; S, 7.7. C,,,1-l, N NaO S requires C, 51.1; H, 4.3; N, 16.6; S, 7.6%).

EXAMPLE 21 Sodium 3-acetoxymethyl-7-(2'chlorobenzamido)-ceph-3- em- 4-carboxylate By using the general method of example 19, 7- aminocephalosporanic acid (3.5 g., 12.8 m.moles), hexamethyldisilazane (5.2 g., 32 m.moles) and 2-chlorobenzoyl chloride [from 2-chlorobenioic acid (2.1 g., 13.4 m.moles)] gave sodium 3-acetoxymethyl-7-(2'-chlorobenzamido)ceph- 3-em-4-carboxylate as a buff solid (4.76 g., 85%). This material crystallized from aqueous acetone as colorless needles, [a] D +86 (C, 1; H O), A,,,,, 260 my. (6 9,900), u (Nujol) 3,260 (NH), 1,760 (B-lactam), 1,738 and 1,750 OCOCl-l 1,660 and 1,538 (-CONH), 1,630 (COO) cm. (Found: C, 46.9; H, 3,2; N, 6.5; S, 7.3. C H CIN =Na0 S requires: C, 47 2;1-1, 3.3; N, 6.5; S, 7.4%).

EXAMPLE 22 Sodium 3-acetoxymethyl-(2, 4, 6-trimethoxybeniamido)- ceph-3-em-4-carboxylate By using the general method of example 19, 7- aminocephalosporanic acid (2.3 g., 8.5 m.moles), hexamethyldisilazane (4.8 g., 30 m.moles) and 2,4,6-trimethoxy benzoyl chloride [from 2,4,6-trimethoxybenzoic acid (2g., 8.7 m.moles)] gave sodium 3-acetoxymethy1-7-(2', 4', 6'- trimethoxybenzamido)-ceph-3-em-4-carboxylate as a brown solid (2.4 g., 58%). Afier successive purification by passage through an alumina column, by charcoaling in ethyl acetate and by precipitation from a solution in dimethylformamide, this material had [a]D +43 (C, 1; H O), A 258 my. (a 12,800), u,,,,,,, (Nujol) 1,760 (Mactam), 1,730 and 1,230 OCOCH 1,660 and 1,510 (-CONH), 1,605 (CO6) cm. (Found: C, 49.1;1'1, 4.0; N, 5.5; S, 6.2. C H N NaO S requires C, 49.2; H, 4.3; N, 5.7; 8,66%).

EXAMPLE 23 7-Bis( 2-thienyl)acetamidocephalosporanic Acid Bis(2-thienyl)acetic acid (4.0 g.)(m.p. 77) was refluxed for 15 min. with thionyl chloride (2.2 ml.). The deep-blue solution was evaporated and treated with 7-aminocephalosporanic acid (5.7 g.) in refluxing ethyl acetate for 1 hr. The cooled mixture was filtered and treated with aniline (5 ml.). After 10 min. the crimson mixture was extracted with 3 percent sodium hydrogen carbonate, and the product was segregated into ethyl acetate. The title compound (3.56 g.) separated from light petroleum. The sodium salt separated from methanolether as crystals, m.p. 235 (decomp), [a],,+83 (C 1.38, H O), M,,,,,, 238 nm. (5 21,850) and 260 nm. (e 10,600) in 0.1 M-phosphate buffer at pH 6), u (Nujol) 1,762 azetidinone), and 1,740 and 1,230 cm (acetate) (Found: C, 47.2; H, 3.7; N, 5.3; S, 19.1 c,.,H,,N Na0,s,, kl-1 0 requires C, 47.1; H, 3.6; N, 5.5; S, 18.9%).

EXAMPLE 24 7-DL-a-Chlorophenylacetylcephalosporanic Acid This compound was made similarly to the foregoing in 65 ;percent yield from 7-aminocephalosporanic acid (5.0 g.). It

had these properties: [a] 81 (c 1, dioxan), A 260 nm. (e

1 8,730) (in 0.1 M-phosphate buffer at pH 6) (Found: C, 48.6;

H, 4.4; CL, 8.3; N, 6.2; S, 7.2. C H CIO N S requires C,

48.8; H, 4.3; CL, 8.0; N, 6.3; S, 7.2%).

We claim:

1. An antibiotic composition comprising from 5 to parts be weight of (A) a broad spectrum cephalosporin antibiotic subject to degradation by a B-lactamase produced by Proteus morgani and from 95 to 5 parts be weight of (B) a compound of the formula s R 0 0.1mm 1 O 0mm wherein R is a phenyl group, and R and R" are each a group selected from the group consisting of lower alkyl, lower alkoxy, lower alkylthio, lower alkanoyloxy, amino, hydroxy and together with the carbon atom to which they are attached a group of the formula S S J wherein Z is a member selected from the group consisting of --(Cll-1,),,- wherein n is an integer from 2 to 4 and a group of the formula (3H5 CH1 and m is or an integer up to 2, (iv) a 3-aryl-5-methyl-isoxazol-4-ylmethyl group wherein aryl is a member selected from the group consisting of phenyl and phenyl substituted by at least one member selected from the group consisting of chloro and bromo, (v) a l-bromobutyl group (vi) a l-chloro-l-phenyl-methyl group, (vii) a thienyl group, (viii) a pyridyl group, (ix) a bis-( thienyl) methyl group and (x) an a-naphthyl group, and R is a group selected from the group consisting of the acetate and azide.

2. An antibiotic composition as claimed in claim 1 wherein the cephalosporin antibiotic (A) is a compound of the formula RAG ONED CHzR 3 @crncomrfl l O V CHziy 7 a Q Q21 where Py is a group selected from the group consisting of N- pyridyl and Npyridyl substituted by a member selected from the group consisting of carbamoyl, lower alkyl, hydroxy, hydroxymethyl, carboxy, lower alkylcarbamoyl and cyano.

4. An antibiotic composition as claimed in claim 2 wherein the cephalosporin antibiotic (A) is cephalon'dine.

5. An antibiotic composition as claimed in claim 2 wherein the cephalosporin antibiotic (A) is cephalothin.

6. An antibiotic composition as claimed in claim 2 wherein the cephalosporin antibiotic (A) is cephaloglycin.

7. An antibiotic composition as claimed in claim 1 wherein the group R in the compound of formula l is a phenyl group containing at least one substituent in an ortho position selected from the group consisting of lower alkyl, lower phenalkyl, lower alkylthio, lower phenalkylthio, lower alkoxy,.

chloro, bromo and iodo.

8. An antibiotic composition as claimed in claim 7 wherein where Q and Q are each radicals selected from the group consisting of lower alkyl, lower alkoxy chloro, bromo and iodo and Q is selected from the group consisting of lower alkyl, lower alkoxy, chloro, bromo, iodo and hydrogen.

9. An antibiotic composition as claimed in claim 8 wherein the group R in the compound of formula I is 0,0- dichlorophenyl.

10. An antibiotic composition as claimed in claim 8 wherein the group R in the compound of formula I is o,o'-dimethoxyphenyl.

l 1. An antibiotic composition as claimed in claim 8 wherein the group R in the compound of formula I is o,o'-dimethylphenyl.

12. An antibiotic composition as claimed in claim 1 wherein the group R in the compound of formula I is a group selected from the group consisting of a 3-o-chlorophenyl-5-methylisoxazol-4-yl and a 30,0-dichlorophenyl-5-methyl-isoxazol-4- yl group.

13. An antibiotic composition as claimed in claim 1 wherein the group R in the compound of formula I is a group of the formula where R is a phenyl group and R and R are each groups selected from the group consisting of lower alkyl, lower alkoxy, lower alkylthio, lower alkanoyloxy, amino, hydroxy and together with the carbon atom to which they are attached a group of the formula wherein Z is a member selected from the group consisting of (CH,),, wherein n is an integer from 2 to 4 and a group of the formula wherein R is as defined above other than the group of the formula c S S and m is 0 or an integer up to 2.

14. An antibiotic composition as claimed in claim I wherein the group R in the compound of formula I is a group of the fonnula where Ar is a phenyl group and Z is (CH,),.- wherein n is an integer from 2 to 4.

15. An antibiotic composition as claimed in claim 1 where the group R in the compound of formula l is a group of the formula where Ar is a phenyl group and wherein Z is the group CH: CH:

. (R'DBL a where m is or an integer up to 2 and R, is a lower alkyl group.

16. An antibiotic composition as claimed in claim 1 comprising a mixture of (A) cephaloridine and (B) 3-acetoxymethyl-7-( 2'6'-dichlorobenzamido )-ceph-3-em-4-carboxylic acid.

17. An antibiotic composition as claimed in claim 16 but wherein compound (B) is present as the sodium or potassium salt thereof.

18. An antibiotic composition as claimed in claim 1 comprising a mixture of (A) cephaloridine and (B) 3-acetoxymethyl-7-(2,4,6'3-em-4-carboxylic acid.

19. An antibiotic composition as claimed in claim 18 wherein compound (B) is present as the sodium or potassium salt thereof.

20. An antibiotic composition as claimed in claim 1 comprising a mixture of (A) cephaloridine and (B) 3-acetoxymethyl-7-( 2',6-dimethoxybenzamido)-ceph-3-em-4-carboxylic acid.

21. An antibiotic composition as claimed in claim 20 but wherein compound (B) is present as the sodium or potassium salt thereof.

22. An antibiotic composition as claimed in claim 1 comprising a mixture of (A) cephaloridine and (B) 7-[3'-(2"- chlorophenyl)-'-methyl-isoxazole-4'-carbonamido-]ceph-3- em-4-carboxylic acid.

23. A composition as claimed in claim 22 but wherein compound (B) is present as the sodium or potassium salt thereof.

24. An antibiotic composition as claimed in claim 1 wherein compounds (A) and (B) are present in a weight ratio of from about 80:20 to about :80 respectively.

25. An antibiotic composition as claimed in claim 1 wherein compounds (A) and (B) are present in a weight ratio of from about 2:1 to about 1:2 respectively.

26. An antibiotic composition as claimed in claim 1 wherein compounds (A) and (B) are present in a weight ratio of about 1:1 respectively.

27. An antibiotic composition as claimed in claim 7 wherein the group R in the compound of formula I is a group selected from the group consisting of 3-phenyl-5-methyl-isoxazol-4-yl, 3-chlorophenyl-5-methyl-isoxazol-4-yl, 3-bromophenyl-5- methyl-isoxazol-4-yl, and 3-iodophenyl-5-methyl-isoxazol-4- yl.

28. A method of conducting antibiotic therapy comprising administering to the host an effective but nontoxic amount of a composition comprising from 5 to 95 parts by weight of (A) a broad spectrum cephalosporin antibiotic which is susceptible to degradation by ,B-lactamase produced by Proteus morgani and from 95 to 5 parts by weight of (B) a second cephalosporin antibiotic resistant to degradation by said B-lactamase and selected to protect said first-mentioned antibiotic against said ,B-lactamase, having the formula CHzR wherein R is a phenyl group, and R and R are each a group selected from the group consisting of lower alkyl, lower alkoxy, lower alkylthio, lower alkanoyloxy, amino, hydroxy and together with the carbon atom to which they are attached a group of the formula wherein Z is a member selected from the group consisting of (CH wherein n is an integer from 2 to 4 and a group of the formula CH; CH:

wherein R is as defined above other than the group of the for mula and m is 0 or an integer up to 2, (iv) a 3-aryl-5-methyl-isoxazol-4-ylmethyl group wherein aryl is a member selected from the group consisting of phenyl and phenyl substituted by at least one member selected from the group consisting of chloro and bromo, (v) a l-bromobutyl group, (vi) a l-chloro-l-phenyl-methyl group, (vii) a thienyl group, (viii) a pyridyl group, (ix) a bis-(thienyl) methyl group and (x) an a-naphthyl group, and R is a group selected from the group consisting of the acetate and azide. 

2. An antibiotic composition as claimed in claim 1 wherein the cephalosporin antibiotic (A) is a compound of the formula wherein R4 is a group selected from the group consisting of 2-thienylmethyl and D- Alpha -amino- Alpha -phenylmethyl groups and R5 is selected from the group consisting of acetate and, in betaine form with the adjacent carboxyl, Py where Py is a group selected from the group consisting of N-pyridyl and N-pyridyl substituted by a member selected from the group consisting of carbamoyl, lower alkyl, hydroxy, hydroxymethyl, carboxy, lower alkylcarbamoyl and cyano.
 3. An antibiotic composition as claimed in claim 2 wherein the cephalosporin antibiotic (A) is a compound of the formula: where Py is a group selected from the group consisting of N-pyridyl and N-pyridyl substituted by a member selected from the group consisting of carbamoyl, lower alkyl, hydroxy, hydroxymethyl, carboxy, lower alkylcarbamoyl and cyano.
 4. An antibiotic composition as claimed in claim 2 wherein the cephalosporin antibiotic (A) is cephaloridine.
 5. An antibiotic composition as claimed in claim 2 wherein the cephalosporin antibiotic (A) is cephalothin.
 6. An antibiotic composition as claimed in claim 2 wherein the cephalosporin antibiotic (A) is cephaloglycin.
 7. An antibiotic composition as claimed in claim 1 wherein the group R1 in the compound of formula I is a phenyl group containing at least one substituent in an ortho position selected from the group consisting of lower alkyl, lower phenalkyl, lower alkylthio, lower phenalkylthio, lower alkoxy, chloro, bromo and iodo.
 8. An antibiotic composition as claimed in claim 7 wherein the group R1 in the compounds of formula I has the structure: where Q1 and Q2 are each radicals selected from the group consisting of lower alkyl, lower alkoxy chloro, bromo and iodo and Q3 is selected from the group consisting of lower alkyl, lower alkoxy, chloro, bromo, iodo and hydrogen.
 9. An antibiotic composition as claimed in claim 8 wherein the group R1 in the compound of formula I is o,o'' -dichlorophenyl.
 10. An antibiotic composition as claimed in claim 8 wherein the group R1 in the compound of formula I is o,o'' -dimethoxy-phenyl.
 11. An antibiotic composition as claimed in claim 8 wherein the group R1 in the compound of formula I is o,o'' -dimeThyl-phenyl.
 12. An antibiotic composition as claimed in claim 1 wherein the group R1 in the compound of formula I is a group selected from the group consisting of a 3-o-chlorophenyl-5-methyl-isoxazol-4-yl and a 3-o,o'' -dichlorophenyl-5-methyl-isoxazol-4-yl group.
 13. An antibiotic composition as claimed in claim 1 wherein the group R1 in the compound of formula I is a group of the formula where R5 is a phenyl group and R6 and R7 are each groups selected from the group consisting of lower alkyl, lower alkoxy, lower alkylthio, lower alkanoyloxy, amino, hydroxy and together with the carbon atom to which they are attached a group of the formula wherein Z is a member selected from the group consisting of -(CH2)n- wherein n is an integer from 2 to 4 and a group of the formula wherein R7 is as defined above other than the group of the formula and m is 0 or an integer up to
 2. 14. An antibiotic composition as claimed in claim 1 wherein the group R1 in the compound of formula I is a group of the formula where Ar is a phenyl group and Z is -(CH2)n- wherein n is an integer from 2 to
 4. 15. An antibiotic composition as claimed in claim 1 where the group R1 in the compound of formula I is a group of the formula where Ar is a phenyl group and wherein Z is the group where m is 0 or an integer up to 2 and R7 is a lower alkyl group.
 16. An antibiotic composition as claimed in claim 1 comprising a mixture of (A) cephaloridine and (B) 3-acetoxymethyl-7-(2'', 6''-dichlorobenzamido)-ceph-3-em-4-carboxylic acid.
 17. An antibiotic composition as claimed in claim 16 but wherein compound (B) is present as the sodium or potassium salt thereof.
 18. An antibiotic composition as claimed in claim 1 comprising a mixture of (A) cephaloridine and (B) 3-acetoxymethyl-7-(2'',4'',6''-trimethylbenzamido)-ceph-3-em-4-carboxylic acid.
 19. An antibiotic composition as claimed in claim 18 wherein compound (B) is present as the sodium or potassium salt thereof.
 20. An antibiotic composition as claimed in claim 1 comprising a mixture of (A) cephaloridine and (B) 3-acetoxymethyl-7-(2'',6''-dimethoxybenzamido)-ceph-3-em-4-carboxylic acid.
 21. An antibiotic composition as claimed in claim 20 but wherein compound (B) is present as the sodium or potassium salt thereof.
 22. An antibiotic composition as claimed in claim 1 comprising a mixture of (A) cephaloridine and (B) 7-(3''-(2''''-chlorophenyl)-5''-methyl-isoxazole-4''-carbonamido-)ceph-3-em-4 -carboxylic acid.
 23. A composition as claimed in claim 22 but wherein compound (B) is present as the sodium or potassium salt thereof.
 24. An antibiotic composition as claimed in claim 1 wherein compounds (A) and (B) are present in a weight ratio of from about 80:20 to about 20:80 respectively.
 25. An antibiotic composition as claimed in claim 1 wherein compounds (A) and (B) are present in a weight ratio of from about 2:1 to about 1:2 respectively.
 26. An antibiotic composition as claimed in claim 1 wherein compounds (A) and (B) are present in a weight ratio of about 1:1 respectively.
 27. An antibiotic composition as claimed in claim 7 wherein the group R1 in the compound of formula I is a group selected from the group consisting of 3-phenyl-5-methyl-isoxazol-4-yl, 3-chlorophenyl-5-methyl-isoxazol-4-yl, 3-bromophenyl-5-methyl-isoxazol-4-yl, and 3-iodophenyl-5-methyl-isoxazol-4-yl.
 28. A method of conducting antibiotic therapy comprising administering to the host an effective but nontoxic amount of a composition comprising from 5 to 95 parts by weight of (A) a broad spectrum cephalosporin antibiotic which is susceptible to degradation by Beta -lactamase produced by Proteus morgani and from 95 to 5 parts by weight of (B) a second cephalosporin antibiotic resistant to degradation by said Beta -lactamase and selected to protect said first-mentioned antibiotic against said Beta -lactamase, having the formula or a salt thereof with nontoxic cations, wherein R1 is a group selected from the group consisting of (i) a phenyl group containing at least one substituent in an ortho position selected from the group consisting of lower alkyl, lower phenalkyl, lower alkylthio, lower phenalkylthio, lower alkoxy, chloro, bromo and iodo, (ii) 3-aryl-5-methyl-isoxazol-4-yl wherein aryl is a member selected from the group consisting of phenyl and phenyl substituted by at least one member selected from the group consisting of chloro and bromo, (iii) 1,1-disubstituted phenalkyl of the formula wherein R5 is a phenyl group, and R6 and R7 are each a group selected from the group consisting of lower alkyl, lower alkoxy, lower alkylthio, lower alkanoyloxy, amino, hydroxy and together with the carbon atom to which they are attached a group of the formula wherein Z is a member selected from the group consisting of -(CH2)n- wherein n is an integer from 2 to 4 and a group of the formula wherein R7 is as defined above other than the group of the formula and m is 0 or an integer up to 2, (iv) a 3-aryl-5-methyl-isoxazol-4-ylmethyl group wherein aryl is a member selected from the group consisting of phenyl and phenyl substituted by at least one member selected from the group consisting of chloro and bromo, (v) a 1-bromobutyl group, (vi) a 1-chloro-1-phenyl-methyl group, (vii) a thienyl group, (viii) a pyridyl group, (ix) a bis-(thienyl) methyl group and (x) an Alpha -naphthyl group, and R2 is a group selected from the group consisting of the acetate and azide. 